U.S. patent number 5,884,105 [Application Number 08/774,778] was granted by the patent office on 1999-03-16 for zoom compact camera.
This patent grant is currently assigned to Asahi Kogaku Kogyo Kabushiki Kaisha. Invention is credited to Kazuyoshi Azegami, Hiroshi Nomura, Takamitsu Sasaki.
United States Patent |
5,884,105 |
Nomura , et al. |
March 16, 1999 |
Zoom compact camera
Abstract
A zoom compact camera arranged such that, during a zooming
procedure, the relative amount and speed of movement along the
optical axis of a first movable barrel with respect to a second
movable barrel are set to be substantially equal to the relative
amount and speed of movement along the optical axis of the second
movable barrel with respect to a third movable barrel. A linear
guide barrel integrally moves with the third movable barrel, and is
provided with a lead-in groove that runs parallel to the optical
axis and the lead-in groove has a through-hole at the rear thereof.
A flexible printed circuit board is arranged such that it extends
rearward from an electrical unit, extends around the rear of the
second movable barrel, extends inside the lead-in groove on the
inner face of the linear guide barrel, extends around the front of
the lead-in groove to be fixed to the outer face of the linear
guide barrel, further extends along the outer face of the linear
guide barrel, and then passes to the inner face of the linear guide
barrel via the through-hole.
Inventors: |
Nomura; Hiroshi (Tokyo,
JP), Azegami; Kazuyoshi (Tokyo, JP),
Sasaki; Takamitsu (Tokyo, JP) |
Assignee: |
Asahi Kogaku Kogyo Kabushiki
Kaisha (Tokyo, JP)
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Family
ID: |
27455775 |
Appl.
No.: |
08/774,778 |
Filed: |
December 30, 1996 |
Foreign Application Priority Data
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Jan 26, 1996 [JP] |
|
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8-012317 |
Feb 14, 1996 [JP] |
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8-027132 |
Feb 14, 1996 [JP] |
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8-027133 |
Mar 14, 1996 [JP] |
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8-057878 |
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Current U.S.
Class: |
396/72; 396/349;
396/542 |
Current CPC
Class: |
H05B
41/325 (20130101); G02B 7/08 (20130101); G03B
7/10 (20130101); G03B 17/02 (20130101); G03B
9/24 (20130101); G03B 7/097 (20130101); G03B
17/14 (20130101); G03B 17/04 (20130101); G02B
7/102 (20130101); G03B 11/043 (20130101); H05K
3/281 (20130101) |
Current International
Class: |
G03B
11/00 (20060101); G03B 11/04 (20060101); G02B
7/08 (20060101); G03B 17/14 (20060101); G03B
7/08 (20060101); G03B 17/02 (20060101); G02B
7/10 (20060101); G03B 17/12 (20060101); G03B
9/24 (20060101); G03B 9/10 (20060101); G03B
7/16 (20060101); G03B 17/04 (20060101); G03B
7/10 (20060101); G03B 7/091 (20060101); G03B
7/097 (20060101); H05B 41/30 (20060101); H05B
41/32 (20060101); H05K 3/28 (20060101); G03B
017/00 () |
Field of
Search: |
;396/72,349,542 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0609913 |
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Jun 1989 |
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EP |
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0407914 |
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Jan 1991 |
|
EP |
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4010278 |
|
Oct 1990 |
|
DE |
|
3219221 |
|
Sep 1991 |
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JP |
|
2231974 |
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Nov 1990 |
|
GB |
|
2244567 |
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Dec 1991 |
|
GB |
|
2244563 |
|
Dec 1991 |
|
GB |
|
Other References
Two United Kingdom Search Reports issued Mar. 11, 1998. .
Copy of a French Search Report, dated Dec. 5, 1997. .
A United Kingdom Search Report, dated Mar. 25, 1997, with UK
Application No. 9701511.9..
|
Primary Examiner: Perkey; W. B.
Attorney, Agent or Firm: Greenblum & Bernstein,
P.L.C.
Claims
What is claimed is:
1. A zoom compact camera comprising:
a camera body;
a first movable barrel;
an electrical unit mounted on said first movable barrel;
a second movable barrel;
a housing for guiding said second movable barrel; and
a flexible printed circuit board for connecting said electrical
unit with a control unit in said camera body;
wherein said first movable barrel and said second movable barrel
are concentrically arranged to telescope during zooming;
wherein said flexible printed circuit board extends with a
predetermined length from said electrical unit around a rear end of
said second movable barrel to the front of said housing; and
wherein during movement of said first movable barrel and said
second movable barrel along the optical axis, the relative amount
and speed of movement of said first movable barrel with respect to
said second movable barrel are substantially equal to the relative
amount and speed of movement of said second movable barrel with
respect to said housing.
2. The camera according to claim 1, further comprising a spring
support, said spring support disposed at the rear end of said
second movable barrel such that said spring support supports said
flexible printed circuit board and urges said flexible printed
circuit board rearward.
3. The camera according to claim 1, said housing comprising a third
movable barrel.
4. The camera according to claim 3, wherein said second movable
barrel houses a linear guide member that integrally moves with said
second movable barrel along the optical axis, said linear guide
member supporting a spring support, and said spring support is
disposed at the rear end of said linear guide member such that said
spring support supports said flexible printed circuit board and
urges said flexible printed circuit board rearward.
5. The camera according to claim 4, wherein said third movable
barrel houses a linear guide barrel that integrally moves with said
third movable barrel along the optical axis, and wherein an inner
face of said linear guide barrel is provided with a lead-in groove,
said lead-in groove extending parallel to the optical axis for
receiving said flexible printed circuit board.
6. The camera according to claim 1, wherein the movement speeds of
the first movable barrel and the second movable barrel are
respectively varied in a linear manner.
7. The camera according to claim 1, wherein said flexible printed
circuit board is secured proximate to the front of said
housing.
8. The camera according to claim 7, wherein said flexible printed
circuit board is secured proximate to the front of said housing by
double-sided tape.
9. A zoom compact camera comprising:
a camera body;
a first movable barrel;
an electrical unit mounted on said first movable barrel;
a second movable barrel;
a third movable barrel;
a linear guide barrel that integrally moves with said third movable
barrel along the optical axis; and
a flexible printed circuit board for connecting said electrical
unit with a control unit in said camera body;
wherein said first movable barrel, said second movable barrel, and
said third movable barrel are concentrically arranged and extend
during zooming;
wherein a lead-in groove is formed on an inner face of said linear
guide barrel parallel to the optical axis and a rear part of said
lead-in groove has a through hole formed therein; and
wherein a portion of said flexible printed circuit board extends
around a rear end of said second movable barrel, extends forwardly
inside said lead-in groove, extends around a front of said lead-in
groove, extends rearwardly along an outer face of said linear guide
barrel, and extends through said through hole to the inner face of
said linear guide barrel.
10. The camera according to claim 9, wherein said second movable
barrel houses a linear guide member that integrally moves with said
second movable barrel along the optical axis, said linear guide
member supporting a spring support, and said spring support is
disposed at the rear end of said linear guide member such that said
spring support supports said flexible printed circuit board and
urges said flexible printed circuit board rearward.
11. The camera according to claim 10, wherein said lead-in groove
receives said flexible printed circuit board during zooming.
12. The camera according to claim 9, wherein the relative amount
and speed of movement along the optical axis of said first movable
barrel with respect to said second movable barrel are substantially
equal to the relative amount and speed of movement along the
optical axis of said second movable barrel with respect to said
third movable barrel.
13. The camera according to claim 12, wherein the moving speeds of
said first movable barrel and said second movable barrel are
respectively varied in a linear manner.
14. The camera according to claim 9, wherein said flexible printed
circuit board is fixed to said outer face of said rectilinear
barrel by double-sided tape.
15. A zoom compact camera comprising:
a camera body;
a first movable barrel;
an electrical unit mounted on said first movable barrel;
a second movable barrel;
a linear guide member that integrally moves with the second movable
barrel along the optical axis;
a third movable barrel;
a linear guide barrel that integrally moves with said third movable
barrel along the optical axis;
a housing that guides said linear guide barrel; and
a flexible printed circuit board for connecting said electrical
unit with a control unit in said camera body;
wherein said first movable barrel, said second movable barrel, and
said third movable barrel are concentrically arranged and extend
during zooming;
wherein a lead-in groove is formed on an inner face of said linear
guide barrel parallel to the optical axis and said lead-in groove
has a through hole formed at a rear part thereof; and
wherein a portion of said flexible printed circuit board extends
from said control unit through a relief hole in said housing unit,
extends between said third movable barrel and said linear guide
barrel to be secured proximate the front of said linear guide
barrel, extends around a front end of said lead-in groove, extends
rearward between said linear guide barrel and said second movable
barrel along said lead-in groove, extends around a rear end of said
second movable barrel and said linear guide member, and extends
forward to said electrical unit.
16. The camera according to claim 15, wherein the relative amount
and speed of movement along the optical axis of said first movable
barrel with respect to said second movable barrel are substantially
equal to the relative amount and speed of movement along the
optical axis of said second movable barrel with respect to said
third movable barrel.
17. The camera according to claim 16, wherein the moving speeds of
said first movable barrel and said second movable barrel are
respectively varied in a linear manner.
18. The camera according to claim 15, wherein said flexible printed
circuit board is fixed to the outer face of said second rectilinear
barrel by double-sided tape.
19. A zoom compact camera comprising:
a camera body;
a movable lens barrel;
a shutter unit;
a fixed lens barrel which supports said movable lens barrel in a
manner enabling movement of said lens barrel along the optical
axis; and
a flexible printed circuit board for providing an electrical link
between said shutter unit and a control unit in said camera
body;
wherein said flexible printed circuit board has at least one
annular ring portion with a predetermined inner diameter and
further comprises two annular rings that have an electrical
connection at a circumferential edge.
20. The camera according to claim 19, wherein the distance,
parallel to the optical axis, between said two annular rings at a
position opposite said electrical connection can be varied.
21. A zoom compact camera comprising:
a movable lens barrel that is movable along the optical axis;
an electrical unit that is mounted on said movable lens barrel;
a control unit; and
a flexible printed circuit board electrically connecting said
electrical unit to said control unit;
wherein said flexible printed circuit board comprises a first
rectilinear portion, an annular portion that includes at least one
annular ring, and a second rectilinear portion; and
wherein said first rectilinear portion extends between said
electrical unit and said annular portion and said second
rectilinear portion extends between said annular portion and said
control unit.
22. The camera according to claim 21,
wherein said annular portion includes two annular rings having an
electrical connection at a first position at a circumferential edge
thereof; and
wherein said first rectilinear portion has an electrical connection
to one of said two annular rings at a second position opposite to
said first position, and said second rectilinear portion has an
electrical connection to another of said two annular rings at a
corresponding third position on said another of said two annular
rings.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a zoom compact camera. In
particular, the present invention relates to a zoom lens barrel
structure and flexible printed circuit board that is provided
within the zoom lens structure.
2. Background of the Invention
In a lens-shutter type of camera having a zooming function ("zoom
compact camera"), a lens barrel, and, in particular, a zoom lens
barrel, is often provided with at least one movable barrel that
moves away from and toward the camera along the optical axis. If an
electrical unit, such as a shutter unit, is housed in the movable
barrel, the shutter unit must be connected to the camera in order
to receive control signals. Thus, the lens barrel is provided with
a flexible printed circuit board (FPC) between the shutter unit and
the camera to allow movement of the movable barrel with respect to
the camera. However, a problem arises in that, as the movable
barrel moves toward the camera, the flexible printed circuit board
becomes slack and can interfere with the movement of the barrels or
with the light coming through the camera aperture.
One conventional measure to control the above problem is to provide
an area for taking-up and paying-out the slack part of the flexible
printed circuit board. However, this method requires an extra
mechanism for taking-up or paying-out the slack or requires extra
space for storage of the slack.
Another measure is to provide a flexible printed circuit board that
is formed with a spiral spring-like shape that is arranged around
the inner diameter of the lens barrel such that, as the movable
barrel extends, the flexible printed circuit board expands like a
spring, and as the movable barrel retracts, the flexible printed
circuit board also retracts like a spring under compression.
However, this method requires that the lens barrel have a diameter
that is sufficient to accommodate the flexible printed circuit
board such that the flexible printed circuit board does not
interfere with the light coming through the camera aperture.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an
improved zoom compact camera in which an electrical unit in a
movable barrel can be connected to a control unit at the camera
body in a simple and compact way.
According to one aspect of the invention, there is provided a zoom
compact camera that includes a camera body, a first movable barrel,
a second movable barrel, a housing, an electrical unit (such as a
shutter unit) mounted on the first movable barrel, and a flexible
printed circuit board for connecting the electrical unit with a
control unit at the camera body.
The first movable barrel and the second movable barrel are
concentrically arranged to telescope during zooming and the housing
guides the second movable barrel. The flexible printed circuit
board is arranged such that it extends with a predetermined length
from the electrical unit around a rear end of the second movable
barrel to the front of the housing.
The camera is further arranged such that, during movement of the
first movable barrel, the second movable barrel and the third
movable barrel, the relative amount and speed of movement along the
optical axis of the first movable barrel with respect to the second
movable barrel are set to be substantially equal to the relative
amount and speed of movement along the optical axis of the second
movable barrel with respect to the housing.
If the movable barrels move in this exemplary manner, the shape of
the flexible printed circuit board adjusts without slacking. That
is, as the shutter unit moves forward with the movement of the
first movable barrel of the flexible printed circuit board is
pulled forward. However, since the first movable barrel is moved
relative to the second movable barrel at the same rate that the
second movable barrel is moved relative to the housing, an
equivalent amount of the flexible printed circuit board is fed from
the part of the flexible printed circuit board that runs between
the second movable barrel and the housing. Thus, slacking of the
flexible printed circuit board is prevented and there is no need to
provide a receiving part for receiving the slack, providing a more
compact camera.
In particular, if a spring support is provided at the rear end of
the second movable barrel, such that the spring support supports
the flexible printed circuit board and urges the flexible printed
circuit board rearward, the flexible printed circuit board will be
guided with no slack.
Alternatively, where the second movable barrel houses a linear
guide member that moves integrally with the second movable barrel
along the optical axis, the linear guide member may be provided
with the spring support.
In a particular exemplary structure, the housing is formed as a
third movable barrel that houses a linear guide barrel that moves
integrally with the third movable barrel along the optical axis. An
inner face of the linear guide barrel is provided with a lead-in
groove that extends parallel to the optical axis for receiving the
flexible printed circuit board. The use of a lead-in groove ensures
that the flexible printed circuit board does not interfere with the
movements of various parts in the lens barrel.
In another exemplary structure, a through-hole is formed at a rear
part of the lead-in groove, and a portion of the flexible printed
circuit board is arranged such that it extends around a rear end of
the second movable barrel, extends forwardly inside the lead-in
groove, extends around a front of the lead-in groove, extends
rearwardly along an outer face of the linear guide barrel, and
extends through the through-hole to the inner face of the linear
guide barrel. This arrangement further secures the flexible printed
circuit board in position to ensure that the flexible printed
circuit board does not interfere with the movement of various parts
in the camera and minimizes the amount of space used by the
flexible printed circuit board.
Preferably, in all of the above-noted exemplary structures, the
movement speeds of the first movable barrel and the second movable
barrel are respectively varied in a linear manner.
Additionally, in all of the above exemplary structures, the
flexible printed circuit board may be secured at or near the front
of the housing, and may be secured to the housing (the third
movable barrel) or the outer face of the linear guide barrel by,
for example, double-sided tape.
In another preferred embodiment, the zoom compact camera includes a
camera body, a movable lens barrel, an electrical unit (such as a
shutter unit), a flexible printed circuit board for providing an
electrical link between the electrical unit and a control unit at
the camera body, and a fixed lens barrel that supports the movable
lens barrel in a manner enabling movement of the movable lens
barrel along the optical axis.
In particular, the flexible printed circuit board has at least one
annular ring portion with a predetermined inner diameter.
In a preferred arrangement, the annular ring portion includes two
annular rings that have an electrical connection at a first
position on a circumferential edge thereof. In this case, the two
annular rings are attached at one side but can separate at an
opposite side such that the annular rings expand and contract in a
bellows-like manner when the movable lens barrel moves forward and
rearward, respectively, along the optical axis.
With this arrangement, the two annular rings fold and unfold in
coordination with the movement of the movable barrel such that
there is no slack in the flexible printed circuit board. Further,
the use of an annular arrangement allows circuit patterns in the
flexible printed circuit board to be split into two paths around
the semi-circular halves of the annular portion such that the width
of the annular portion is half of the width of the other portions
of the flexible printed circuit board. Thus, the annular portion
does not interfere with the light entering the camera aperture.
In a particular exemplary structure, the flexible printed circuit
board may further include a first rectilinear part and a second
rectilinear part. The first rectilinear portion has an electrical
connection to one of the two annular rings at a second position
opposite to the first position and the second rectilinear portion
has an electrical connection to the other of the two annular rings
at a corresponding third position on the other of the two annular
rings. With this arrangement, the two annular rings are supported
by the first rectilinear portion and the second rectilinear portion
and are folded and unfolded, as described above, by the movement of
the first rectilinear portion and the second rectilinear
portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged schematic perspective view showing a part of
a zoom lens barrel;
FIG. 2 is a schematic perspective view showing the part of the zoom
lens barrel shown in FIG. 1 in an engaged state;
FIG. 3 is an enlarged exploded perspective view showing a part of
the zoom lens barrel;
FIG. 4 is a schematic perspective view illustrating a state where
an AF/AE shutter unit of the zoom lens barrel is mounted to a first
movable barrel;
FIG. 5 is an exploded perspective view illustrating main parts of
the AF/AE shutter unit of the zoom lens barrel;
FIG. 6 is an external schematic perspective view of a third movable
barrel of the zoom lens barrel;
FIG. 7 is a front elevational view of a fixed lens barrel block of
the zoom lens barrel;
FIG. 8 is a sectional view of an upper part of the zoom lens barrel
in a maximum extended state;
FIG. 9 is a sectional view of an upper part of the zoom lens barrel
in a housed state;
FIG. 10 is an exploded perspective view of the overall structure of
the zoom lens barrel;
FIG. 11 is a block diagram of a controlling system for controlling
an operation of the zoom lens barrel;
FIG. 12 is an exploded perspective view showing the major parts of
the flexible printed circuit board guiding structure of the zoom
lens barrel;
FIG. 13 is an enlarged perspective view showing the rectilinear
guide member of the zoom lens barrel;
FIG. 14 is a cross-section showing a spring support at an end of
the rectilinear guide member of the zoom lens barrel;
FIG. 15 is an external perspective view showing the condition of
the flexible printed circuit board in relation to the first movable
barrel;
FIG. 16 is an external perspective view showing the condition of
the flexible printed circuit board in relation to the second
movable barrel;
FIG. 17 is an external perspective view showing the condition of
the flexible printer circuit board in relation to the rectilinear
guide barrel;
FIG. 18 is an external perspective view showing the condition of
the flexible printed circuit board in relation to the third movable
barrel;
FIG. 19 is an external perspective view of the fixed lens barrel
block of the zoom lens barrel;
FIG. 20 is a front view of the fixed lens barrel block of the zoom
lens barrel;
FIG. 21 is a rear view of the fixed lens barrel block of the zoom
lens barrel;
FIG. 22 is a development of the rectilinear guide barrel of the
zoom lens barrel;
FIG. 23 is an enlarged development of major parts of the
rectilinear guide barrel of the zoom lens barrel;
FIG. 24 is a development of the second movable barrel of the zoom
lens barrel;
FIG. 25 is an enlarged development of major parts of the second
movable barrel of the zoom lens barrel;
FIG. 26 is a graph showing the correlation between the rotation
angle of the third movable barrel of the zoom lens barrel and the
respective amounts of extensions of the first and second movable
barrels of the zoom lens barrel;
FIG. 27 is a sectional view of an upper part of the zoom lens
barrel in a maximum extended state showing the flexible printed
circuit board of the second embodiment;
FIG. 28 is a sectional view of an upper part of the zoom lens
barrel in a housed state showing the flexible printed circuit board
of the second embodiment;
FIG. 29 is a plan view of the flexible printed circuit board of the
second embodiment; and
FIG. 30 is a perspective view of the flexible printed circuit board
of the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of a lens-shutter type of camera having a
zooming function (referred to as a "zoom compact camera" or a "zoom
lens camera") will be described below.
The concept of the zoom lens camera will now be described with
reference to FIG. 11. FIG. 11 is a schematic representation of
various elements which comprise a zoom lens camera.
The zoom lens camera is provided with a three-stage delivery-type
zoom lens barrel 10 having three movable barrels, namely a first
movable barrel 20, a second movable barrel 19 and a third movable
barrel 16, which are concentrically arranged in this order from an
optical axis O. In the zoom lens barrel 10, two lens groups are
provided, namely a front lens group L1 having positive power and a
rear lens group L2 having negative power.
In the camera body, a whole optical unit driving motor controller
60, a rear lens group driving motor controller 61, a zoom operating
device 62, a focus operating device 63, an object distance
measuring apparatus 64, a photometering apparatus 65, and an AE
(i.e., automatic exposure) motor controller 66, are provided.
Although the specific focusing system of the object distance
measuring apparatus 64, which is used to provide information
regarding the object-to-camera distance, does not form part of the
present invention, one such suitable system is disclosed in
commonly assigned U.S. patent application Ser. No. 08/605,759,
filed on Feb. 22, 1996, the entire disclosure of which is expressly
incorporated by reference herein. Although the focusing systems
disclosed in U.S. patent application Ser. No. 08/605,759 are of the
so-called "passive" type, other known autofocus systems (e.g.,
active range finding systems such as those based on infrared light
and triangulation) may be used. Similarly, a photometering system
as disclosed in the above-noted U.S. patent application Ser. No.
08/605,759 could be implemented as photometering apparatus 65.
The zoom operative device 62 may comprise as, for example, a
manually-operable zoom operating lever (not shown) provided on the
camera body or a pair of zoom buttons, e.g., a "wide" zoom button
and a "tele" zoom button, (not shown) provided on the camera body.
When the zoom operating device 62 is operated, the whole optical
unit driving motor controller 60 drives a whole optical unit
driving motor 25 to move the front lens group L1 and the rear lens
group L2, rearwardly or forwardly. In the following explanation,
forward and rearward movements of the lens groups L1 and L2 by the
whole optical unit driving motor controller 60 (the motor 25) are
referred to as the movement toward "tele" and the movement toward
"wide" respectively, since forward and rearward movements of the
lens groups L1 and L2 occur when the zoom operating device 62 is
operated to "tele" and "wide" positions.
The image magnification of the visual field of a zoom finder 67
provided in the camera body varies sequentially to the variation of
the focal length through the operation of the zoom operating device
62. Therefore, the photographer may perceive the variation of the
set focal length through the operation of the zoom operating device
62, by observing the variation of image magnification of the visual
field of the finder. In addition, the focal length, set by the
operation of the zoom operating device 62, may be indicated as a
value on an LCD (liquid crystal display) panel (not shown) or the
like.
When the focus operating device 63 is operated, the whole optical
unit driving motor controller 60 drives the whole optical unit
driving motor 25. At the same time the rear lens group driving
motor controller 61 drives a rear lens group driving motor 30. The
driving of the whole optical unit driving motor controller 60 and
the rear lens group driving motor controller 61, moves the front
and rear lens groups L1 and L2 to respective positions
corresponding to a set focal length and a detected object distance,
such that the zoom lens is focused on the object.
Specifically, the focus operating device 63 is provided with a
release button (not shown) provided on an upper wall of the camera
body. A photometering switch and a release switch (both not shown)
are synchronized with the release button. When the release button
is half-depressed (half-step), the photometering switch is turned
ON, and the object distance measuring and photometering commands
are respectively input to the object distance measuring apparatus
64 and the photometering apparatus 65.
When the release button is fully depressed (full step), the release
switch is turned ON, and according to the result of object distance
measuring command and a set focal length, the whole optical unit
driving motor 25 and the rear lens group driving motor 30 are
driven. In addition, the focusing operation, in which the front
lens group L1 and the rear lens group L2 move to the focusing
position, is executed. Further, an AE motor 29 of an AF/AE (i.e.,
autofocus/autoexposure) shutter unit (FIG. 9) is driven via the AE
motor controller 66 to actuate a shutter 27. During the shutter
action, the AE motor controller 66 drives the AE motor 29 to open
shutter blades 27a of the shutter 27 for a specified period of time
according to the photometering information output from the
photometering apparatus 65.
When the zoom operating device 62 is operated, the zoom operating
device 62 drives the whole optical unit driving motor 25 to move
the front and rear lens groups L1 and L2 together as a whole along
the optical axis O (optical axis direction). Simultaneous with such
a movement, the rear lens group driving motor 30 may also be driven
via the rear lens group driving motor controller 61 to move the
rear lens group L2 relatively with respect to the first lens group
L1. However, this above-described operation is not performed under
the conventional concept of zooming, in which the focal length is
varied sequentially while maintaining an in-focus condition. When
the zoom operating device 62 is operated, the front lens group L1
and the rear lens group L2 move in the optical axis direction,
without varying the distance therebetween, by driving only the
whole optical unit driving motor 25.
During the zooming operation, an in-focus condition cannot be
maintained at all times with respect to an object located at a
specific distance. However, this is not a problem in a lens-shutter
type camera, since the image of the object is not observed through
the photographing optical system, but rather through the finder
optical system, that is provided separate from the photographing
optical system. Thus, it is sufficient that the in-focus condition
is obtained when the shutter is released. Accordingly, when the
release button is fully depressed, the focusing operation (focus
adjusting operation) is carried out by moving at least one of the
whole optical unit driving motor 25 and the rear lens group driving
motor 30. In such a manner, when the focus operating device 63 is
operated and since each of the two lens groups L1, L2 can be driven
independently, the position of the lens groups L1, L2 can be
flexibly controlled.
An embodiment of the zoom lens barrel according to the above
concept will be described with reference to mainly FIGS. 9 and
10.
The overall structure of the zoom lens barrel 10 will now be
described.
The zoom lens barrel 10 is provided with the first movable barrel
20, the second movable barrel 19, the third movable barrel 16, and
a fixed lens barrel block 12. The third movable barrel 16 engages a
cylindrical portion 12p of the fixed lens barrel block 12, and
moves along the optical axis O upon being rotated. A linear guide
barrel 17 is provided on an inner periphery of the third movable
barrel 16 which is rotationally restricted. The linear guide barrel
17 and the third movable barrel 16 move together as a whole along
the optical axis O, with the third movable barrel 16 rotating
relative to the linear guide barrel 17. The first movable barrel 20
moves along the optical axis O and is rotationally restricted. The
second movable barrel 19 rotatably moves relative to the linear
guide barrel 17 and the first movable barrel 20 along the optical
axis O. The whole optical unit driving motor 25 is secured to the
fixed lens barrel block 12. A shutter mounting stage 40 is secured
to the first movable barrel 20. The AE motor 29 and the rear lens
group driving motor 30 are mounted on the shutter mounting stage
40. The front lens group L1 and the rear lens group L2 are
respectively supported by a lens supporting barrel (lens supporting
annular member) 34 and a lens supporting barrel 50.
The fixed lens barrel block 12 is fixed in front of an aperture
plate 14 fixed to the camera body. The aperture plate 14 is
provided on a center thereof with a rectangular-shaped aperture 14a
which forms the limits of each exposed frame. The fixed lens barrel
block 12 is provided, on an inner periphery of the cylindrical
portion 12p thereof, with a female helicoid 12a, and also a
plurality of linear guide grooves 12b each extending parallel to
the optical axis O, i.e., extending in the optical axis direction.
At the bottom of one of the linear guide grooves 12b, namely 12b',
a code plate 13a, having a predetermined code pattern, is fixed.
The code plate 13a extends in the optical axis direction and
extends substantially along the whole of the length of the fixed
lens barrel block 12. The code plate 13a is part of a flexible
printed circuit board 13 positioned outside the fixed lens barrel
block 12.
A gear housing 12c is provided as shown in FIGS. 7 or 10 in the
fixed lens barrel block 12. The gear housing 12c is recessed
outwardly from an inner periphery of the cylindrical portion 12p of
the fixed lens barrel block 12 in a radial direction while
extending in the optical axis direction. In the gear housing 12c, a
driving pinion 15, extending in the optical axis direction, is
rotatably positioned. Both ends of an axial shaft 7 of the driving
pinion 15 are rotatably supported by a supporting hollow 4, which
is provided in the fixed lens barrel block 12, and a supporting
hollow 31a, which is provided on a gear supporting plate 31 fixed
on the fixed lens barrel block 12 by set screws (not shown),
respectively. Part of the teeth of the driving pinion 15 project
inwardly from the inner periphery of the cylindrical portion of the
fixed lens barrel block 12, so that the driving pinion 15 meshes
with an outer peripheral gear 16b of the third movable barrel 16,
as shown in FIG. 7.
A plurality of linear guide grooves 16c are formed on an inner
periphery of the third movable barrel 16, each of which extends
parallel to the optical axis O. At an outer periphery of the rear
end of the third movable barrel 16, a male helicoid 16a and the
aforementioned outer peripheral gear 16b are provided as shown in
FIG. 6. The male helicoid 16a engages with the female helicoid 12a
of the fixed lens barrel block 12. The outer peripheral gear 16b
engages with the driving pinion 15. The driving pinion 15 has an
axial length sufficient to engage with the outer peripheral gear
16b throughout the entire range of movement of the third movable
barrel 16 in the optical axis direction.
As shown in FIG. 10, the linear guide barrel 17 is provided with a
rear end flange 17d on a rear part of an outer periphery. The rear
end flange 17d has a plurality of engaging projections 17c each
projecting away from the optical axis O in a radial direction. The
linear guide barrel 17 is further provided with an anti-dropping
flange 17e in front of the rear end flange 17d. A circumferential
groove 17g is formed between the rear end flange 17d and the
anti-dropping flange 17e. The anti-dropping flange 17e has a radius
which is smaller than the rear end flange 17d. The anti-dropping
flange 17e is provided with a plurality of cutout portions 17f.
Each of the cutout portions 17f allows a corresponding engaging
projection 16d to be inserted into the circumferential groove 17g,
as shown in FIG. 9.
The third movable barrel 16 is provided with a plurality of
engaging projections 16d on an inner periphery of the rear end
thereof. Each of the engaging projections 16d projects towards the
optical axis O in a radial direction. By inserting the engaging
projections 16d into the circumferential groove 17g, through the
corresponding cutout portions 17f, the engaging projections 16d are
positioned in the circumferential groove 17g between the flanges
17d and 17e (see FIG. 9). By rotating the third movable barrel 16
relative to the linear guide barrel 17, the engaging projections
16d are engaged with the linear guide barrel 17.
An aperture plate 23 having a rectangular-shaped aperture 23a
approximately the same shape as the aperture 14a is fixed on the
rear end of the linear guide barrel 17.
The relative rotation of the linear guide barrel 17, with respect
to the fixed lens barrel block 12, is restricted by the slidable
engagement of the plurality of engaging projections 17c with the
corresponding linear guide grooves 12b, formed parallel to the
optical axis O.
A contacting terminal 9 is fixed to one of the engaging projections
17c, in particular projection 17c'. The contacting terminal 9 is in
slidable contact with the code plate 13a, fixed to the bottom of
the linear guide groove 12b', to generate signals corresponding to
focal length information during zooming. On the inner periphery of
the linear guide barrel 17 a plurality of linear guide grooves 17a
are formed, each extending parallel to the optical axis O. A
plurality of lead slots 17b are also formed on the linear guide
barrel 17 as shown in FIG. 10. The lead slots 17b are each formed
oblique (inclined) to the optical axis O.
The second movable barrel 19 engages with the inner periphery of
the linear guide barrel 17. A plurality of lead grooves 19c are
provided on the inner periphery of the second movable barrel 19, in
a direction inclined oppositely to the lead slots 17b. A plurality
of follower projections 19a are provided On the outer periphery of
the rear end of the second movable barrel 19. Each of the follower
projections 19a has a trapezoidal cross-sectional shape projecting
away from the optical axis O in a radial direction. Follower pins
18 are positioned in the follower projections 19a. Each follower
pin 18 consists of a ring member 18a, and a center fixing screw 18b
which supports the ring member 18a on the corresponding follower
projection 19a. The follower projections 19a are in slidable
engagement with the lead slots 17b of the linear guide barrel 17,
and the follower pins 18 are in slidable engagement with the linear
guide grooves 16c of the third movable barrel 16. With such an
arrangement, when the third movable barrel 16 rotates, the second
movable barrel 19 rotates while moving linearly in the optical axis
direction.
The first movable barrel 20 is engaged to the inner periphery of
the second movable barrel 19. A plurality of follower pins 24 are
provided on an outer periphery of the rear of the first movable
barrel 20, each engaging with the corresponding inner lead groove
19c. In addition, the first movable barrel 20 is guided linearly by
a linear guide member 22. The first movable barrel 20 is provided
at the front end thereof with a decorative plate 41.
As shown in FIGS. 1 and 2, the linear guide member 22 is provided
with an annular member 22a, a pair of guide legs 22b and a
plurality of engaging projections 28. The pair of guide legs 22b
project from the annular member 22a in the optical axis direction.
The plurality of engaging projections 28 each project from the
annular member 22a away from the optical axis O in a radial
direction. The engaging projections 28 slidably engage with the
linear guide grooves 17a. The guide legs 22b are respectively
inserted into linear guides 40c between the inner peripheral
surface of the first movable barrel 20 and the AF/AE shutter unit
21.
The annular member 22a of the linear guide member 22 is connected
to the rear of the second movable barrel 19, such that the linear
guide member 22 and the second movable barrel 19 move along the
optical axis O as a whole, and in addition are capable of
relatively rotating with respect to each other around the optical
axis O. The linear guide member 22 is further provided, on the
outer periphery of the rear end thereof, with a rear end flange
22d. The linear guide member 22 is also provided with an
anti-dropping flange 22c in front of the rear end flange 22d. A
circumferential groove 22f is formed between the rear end flange
22d and the anti-dropping flange 22c. The anti-dropping flange 22c
has a radius which is smaller than the rear end flange 22d. As
shown in FIGS. 1 or 2, the anti-dropping flange 22c is provided
with a plurality of cutout portions 22e, each allowing a
corresponding engaging projection 19b to be inserted into the
circumferential groove 22f (see FIG. 9).
A plurality of engaging projections 19b, each projecting towards
the optical axis O in a radial direction are provided on an inner
periphery of the rear end of the second movable barrel 19. By
inserting the engaging projections 19b into the circumferential
groove 22f through the corresponding cutout portions 22e, the
engaging projections 19b are positioned in the circumferential
groove 22f between the flanges 22c and 22d. By rotating the second
movable barrel 19 relative to the linear guide member 22, the
engaging projections 19b are engaged with the linear guide member
22. With the above structure, when the second movable barrel 19
rotates in the forward or reverse rotational direction, the first
movable barrel 20 moves linearly, forwardly or rearwardly along the
optical axis O, but is restricted from rotating.
A barrier apparatus 35 having barrier blades 48a and 48b is mounted
to the front of the first movable barrel 20. On an inner peripheral
face of the first movable barrel 20 the AF/AE shutter unit 21 is
engaged and fixed, as shown in FIG. 8. The AF/AE shutter unit 21
includes the shutter 27, which consists of three shutter blades 27a
The AF/AE shutter unit 21 is provided with a plurality of fixing
holes 40a formed at even angular intervals on the outer periphery
of the shutter mounting state 40. Only one of the fixing holes 40a
appears in each of FIGS. 1-5.
The aforementioned plurality of follower pins 24, which engage with
the inner lead grooves 19c, also serve as device for fixing the
AF/AE shutter unit 21 to the first movable barrel 20. The follower
pins 24 are inserted and fixed in holes 20a, formed on the first
movable barrel 20, and in the fixing holes 40a. With this
arrangement the AF/AE shutter unit 21 is secured to the first
movable barrel 20 as shown in FIG. 4. In FIG. 4 the first movable
barrel 20 is indicated by phantom lines. The follower pins 24 may
be fixed by an adhesive, or the pins 24 may comprise as screws
which are screwed into the fixing holes 40a.
As illustrated in FIGS. 5 and 10, the AF/AE shutter unit 21 is
provided with the shutter mounting state 40, a shutter blade
supporting ring 46 which is fixed on the rear of the shutter
mounting stage 40 so as to be located inside the shutter mounting
stage 40, and the lens supporting barrel 50 supported such that it
is movable relative to the shutter mounting stage 40. The lens
supporting barrel 34, the AE motor 29, and the rear lens group
driving motor 30, are supported on the shutter mounting stage 40.
The shutter mounting stage 40 is provided with an annular member
40f having a circular aperture 40d. The shutter mounting stage 40
is also provided with three legs 40b which project rearwardly with
respect to the camera body from the annular member 40f. Three slits
are defined between the three legs 40b. Two of the slits comprise
the aforementioned linear guides 40c, which slidably engage with
the respective pair of guide legs 22b of the linear guide member
22, so as to guide the movement of the linear guide member 22.
The shutter mounting stage 40 supports an AE gear train 45 which
transmits a rotation of the AE motor 29 to the shutter 27, a lens
driving gear train 42 which transmits rotation of the rear lens
group driving motor 30 to a screw shaft 43, photo-interrupters 56,
57a and 57b which are connected to a flexible printed circuit board
6, and rotating disks 58, 59a and 59b, having a plurality of
radially formed slits provided in the circumferential direction. An
encoder for detecting whether the rear lens group driving motor 30
is rotating and for detecting an amount of rotation of the rear
lens group driving motor 30 consists of the photo-interrupters 57a,
57b and the rotating disks 59a, 59b. An AE motor encoder for
detecting whether the AE motor 29 is rotating and for detecting an
amount of rotation of the AE motor 29 consists of the
photo-interrupter 56 and the rotating disk 58.
The shutter 27, a supporting member 47 which pivotally supports the
three shutter blades 27a of the shutter 27, and a circular driving
member 49, which provides rotative power to the shutter blades 27a,
are positioned between the shutter mounting stage 40 and the
shutter blade supporting ring 46, secured to the shutter mounting
stage 40. The circular driving member 49 is provided with three
operating projections 49a at even angular intervals, which
respectively engage with each of the three shutter blades 27a. As
shown in FIG. 5, the shutter blade supporting ring 46 is provided,
at a front end thereof, with a circular aperture 46a and with three
supporting holes 46b positioned at even angular intervals around
the circular aperture 46a. Two deflection restricting surfaces 46c
are formed on the outer periphery of the shutter blade supporting
ring 46. Each deflection restricting surface 46c is exposed
outwardly from the corresponding linear guide 40c and slidably
supports the inner peripheral face of the corresponding guide leg
22b.
The supporting member 47, positioned in front of the shutter blade
supporting ring 46, is provided with a circular aperture 47a,
aligned with the circular aperture 46a of the shutter blade
supporting ring 46, and with three pivotal shafts 47b (only one of
which is illustrated in FIG. 10) at respective positions opposite
the three supporting holes 46b. Each shutter blade 27a is provided
at one end thereof with a hole 27b into which the corresponding
pivotal shaft 47b is inserted, such that each shutter blade 27a is
rotatable about the corresponding pivotal shaft 47b. The major part
of each shutter blade 27a, that extends normal to the optical axis
O from the pivoted end, is formed as a light-interceptive portion.
All three light-interceptive portions of the shutter blades 27a
together prevent ambient light, which enters the front lens group
L1, from entering the circular apertures 46a and 47a when the
shutter blades 27a are closed. Each shutter blade 27a is further
provided, between the hole 27b and the light-interceptive portion
thereof, with a slot 27c, through which the corresponding operating
projection 49a is inserted. The supporting member 47 is fixed to
the shutter blade supporting ring 46 in such a manner that, each
shaft 47b, which supports the corresponding shutter blade 27a, is
engaged with the corresponding supporting hole 46b of the shutter
blade supporting ring 46.
A gear portion 49b is formed on a part of the outer periphery of
the circular driving member 49. The gear portion 49b meshes with
one of the plurality of gears in the gear train 45 to receive the
rotation force from the gear train 45. The supporting member 47 is
provided, at respective positions close to the three pivotal shafts
47b, with three arc grooves 47c each arched along a circumferential
direction. The three operating projections 49a of the circular
driving ring 49 engage with the slots 27c of the respective shutter
blades 27a through the respective arc grooves 47c. The shutter
blade supporting ring 46 is inserted from the rear of the shutter
mounting stage 40, to support the circular driving ring 49, the
supporting member 47 and the shutter 27, and is fixed on the
shutter mounting stage 40 by set screws 90 respectively inserted
through holes 46d provided on the shutter blade supporting ring
46.
Behind the shutter blade supporting ring 46, the lens supporting
barrel 50, supported to be able to move relative to the shutter
mounting stage 40 via guide shafts 51 and 52, is positioned. The
shutter mounting stage 40 and the lens supporting barrel 50 are
biased in opposite directions away from each other by a coil spring
3 fitted on the guide shaft 51, and therefore play between the
shutter mounting stage 40 and the lens supporting barrel 50 is
reduced. In addition, a driving gear 42a, provided as one of the
gears in the gear train 42, is provided with a female thread hole
(not shown) at the axial center thereof, and is restricted to move
in the axial direction. The screw shaft 43 one end of which is
fixed to the lens supporting barrel 50, engages with the female
thread hole of the driving gear 42a. Accordingly, the driving gear
42a and the screw shaft 43 together constitute a feed screw
mechanism. In such a manner, when the driving gear 42a rotates
forwardly or reversely due to driving by the rear lens group
driving motor 30, the screw shaft 43 moves forwardly or rearwardly
with respect to the driving gear 42a, and therefore the lens
supporting barrel 50, which supports the rear lens group L2, moves
relative to the front lens group L1.
A holding member 53 is fixed at the front of the shutter mounting
stage 40. The holding member 53 holds the motors 29 and 30 between
the holding member 53 and the shutter mounting stage 40. The
holding member 53 has a metal holding plate 55 fixed at the front
thereof by set screws (not shown). The motors 29, 30 and the
photo-interrupters 56, 57a and 57b are connected to the flexible
printed circuit board 6. One end of the flexible printed circuit
board 6 is fixed to the shutter mounting stage 40.
After the first, second and third movable barrels 20, 19 and 16,
and the AF/AE shutter unit 21, etc. are assembled, the aperture
plate 23 is fixed to the rear of the linear guide barrel 17, and a
supporting member 33 having a circular shape is fixed at the front
of the fixed lens barrel block 12.
In the above-described embodiment of the zoom lens barrel 10,
although the zoom lens optical system consists of two movable lens
groups, namely the front lens group L1 and the rear lens group L2,
it should be understood that the present invention is not limited
to the present embodiment disclosed above, but the present
invention may also be applied to another type of zoom lens optical
system including one or more fixed lens groups.
In addition, in the above embodiment, the rear lens group L2 is
supported on the AF/AE shutter unit 21, and the AE motor 29 and the
rear lens group driving motor 30 are mounted to the AF/AE shutter
unit 21. With such a structure, the structure for supporting the
front and rear lens groups L1 and L2 and the structure for driving
the rear lens group L2 are both simplified. Instead of adopting
such a structure, the zoom lens barrel 10 may also be constructed
in such a manner that the rear lens group L2 is not supported by
the AF/AE shutter unit 21, which is provided with the shutter
mounting stage 40, the circular driving member 49, the supporting
member 47, the shutter blades 27, the shutter blade supporting ring
46 and the like, and that the rear lens group L2 is supported by
any supporting member other than the AF/AE shutter unit 21.
The operation of the zoom lens barrel 10, by rotation of the whole
optical unit driving motor 25 and the rear lens group driving motor
30, will now be described with reference to FIGS. 8 and 9.
As shown in FIG. 9, when the zoom lens barrel 10 is at the most
retracted (withdrawn) position, i.e., the lens-housed condition.
When the power switch is turned ON, the drive shaft of the whole
optical unit driving motor 25 is driven to rotate in the forward
rotational direction by a small amount. This rotation of the motor
25 is transmitted to the driving pinion 15 through a gear train 26,
which is supported by a supporting member 32 integrally formed with
the fixed lens barrel block 12, to rotate the third movable barrel
16 in one predetermined rotational direction to advance forwardly
along the optical axis O. Therefore, the second movable barrel 19
and the first movable barrel 20 are each advanced by a small amount
in the optical axis direction, along with the third movable barrel
16. Consequently, the camera is placed in a state capable of
photographing, with the zoom lens positioned at the widest
position, i.e., the wide end. In this state, the focal length may
be detected in accordance with the amount of relative movement
between the sliding movement of the code plate 13a and the
contacting terminal 9 as the linear guide barrel 17 moves with
respect to the fixed lens barrel block 12.
In the photographable state as above described, when the
aforementioned zoom operating lever is manually moved towards a
"tele" side, or the "tele" zoom button is manually depressed to be
turned ON, the whole optical unit driving motor 25 is driven to
rotate in the forward rotational direction through the whole
optical unit driving motor controller 60. The rotation of the
optical unit driving motor 25 causes the third movable barrel 16 to
rotate in the rotational direction to advance along the optical
axis O via the driving pinion 15 and the outer peripheral gear 16b.
Therefore, the third movable barrel 16 is advanced from the fixed
lens barrel block 12, according to the relationship between the
female helicoid 12a and the male helicoid 16a. At the same time,
the linear guide barrel 17 moves forwardly along the optical axis O
together with the third movable barrel 16, without relatively
rotating with respect to the fixed lens barrel block 12, and in
accordance with the relationship between the engaging projections
17c and the linear guide grooves 12b. At this time, the
simultaneous engagement of the follower pins 18 with the respective
lead slots 17b and the linear guide grooves 16c causes the second
movable barrel 19 to move forwardly relative to the third movable
barrel 16 in the optical axis direction. In addition, the second
movable barrel 10 rotates together with the third movable barrel 16
in the same rotational direction relative to the fixed lens barrel
block 12. The first movable barrel 20 moves forwardly from the
second movable barrel 19 along the optical axis O together with the
AF/AE shutter unit 21, without relatively rotating with respect to
the fixed lens barrel block 12 due to the above-noted structures in
which the first movable barrel 20 is guided linearly by the linear
guide member 22 and in which the follower pins 24 are guided by the
lead grooves 19c. During such movements, according to the fact that
the moving position of the linear guide barrel 17 with respect to
the fixed lens barrel block 12 is detected through the relative
slide between the code plate 13a and the contacting terminal 9, the
focal length is detected.
Conversely, when the zoom operating lever is manually moved towards
a "wide" side, or the "wide" zoom button is manually depressed to
be turned ON, the whole optical unit driving motor 25 is driven to
rotate in the reverse rotational direction by the whole optical
unit driving motor controller 60, so that the third movable barrel
16 rotates in the rotational direction to retract into the fixed
lens barrel block 12 together with the linear guide barrel 17. At
the same time, the second movable barrel 19 is retracted into the
third movable barrel 16 while rotating in the same direction as
that of the third movable barrel 16, and the first movable barrel
20 is retracted into the rotating second movable barrel 19 together
with the AF/AE shutter unit 21. During the above retraction
driving, similar to the case of advancing driving as above
described, the rear lens group driving motor 30 is not driven.
While the zoom lens barrel 10 is driven during the zooming
operation, the front lens group L1 and the rear lens group L2 move
as a whole, since the rear lens group driving motor 30 is not
driven, which maintains a constant distance between the lens
groups, as shown in FIG. 8. The focal length is input via the zoom
code plate 13a and the contacting terminal 9 is indicated on an LCD
panel (not shown) provided on the camera body.
At any focal length, when the release button is depressed by a
half-step, the object distance measuring apparatus 64 is actuated
to measure an object distance. At the same time, the photometering
apparatus 65 is actuated to measure an object brightness.
Thereafter, when the release button is fully depressed, the whole
optical unit driving motor 25 and the rear lens group driving motor
30 are each driven by respective amounts each corresponding to the
focal length information set in advance and the object distance
information obtained from the object distance measuring apparatus
64, so that the front and rear lens groups L1 and L2 are
respectively moved to specified positions to obtain a specified
focal length and also to bring the object into focus. Immediately
after the object is brought into focus, via the AE motor controller
66, the AE motor 29 is driven to rotate the circular driving member
49 by an amount corresponding to the object brightness information
obtained from the photometering apparatus 65, so that the shutter
27 is driven to open the shutter blades 27a by a predetermined
amount which satisfies the required exposure. Immediately after the
three shutter blades 27a are opened and subsequently closed, the
whole optical unit driving motor 25 and the rear lens group driving
motor 30 are both driven to move the front lens group L1 and the
rear lens group L2 to respective initial positions at which they
were at prior to a shutter release.
An embodiment of the zoom compact camera having an exemplary
flexible printed circuit board guiding structure will now be
described with reference to FIGS. 8, 9 and 12-26.
As shown in FIGS. 12 and 19, the fixed lens barrel block 12 is
provided with a barrel portion 12p, an FPC fixing part 12m, and a
supporting part 32. The supporting part 32 is formed on one side of
the barrel portion 12p and the FPC fixing part 12m is formed on the
other side, opposite the supporting part 32.
The supporting part 32 supports, at the rear thereof, the whole
optical unit driving motor 25 and, at the front thereof, a gear
train 26, comprised of a plurality of gears as shown in FIG.
10.
The FPC fixing part 12m is formed projecting sideways near the
front of the barrel portion 12p. A flexible printed circuit board
relief hole 12k (FPC relief hole) is formed on the barrel portion
12p to the rear of the FPC fixing part 12m. The FPC relief hole 12k
is formed parallel to the optical axis O and is sufficiently large
to allow the flexible printed circuit board 6 to protrude
outward.
The fixing part 12m is provided with a plurality of fixing
protrusions 12n and the flexible printed circuit board 6 is
attached to the fixing part 12m by fitting a plurality of fixing
holes 6i (see, for example, FIG. 15) to the plurality of fixing
protrusions 12n.
The flexible printed circuit board 6 connects the AF/AE shutter
unit 21 with a control unit 75 (see FIG. 8) that is mounted on the
camera body. The control unit 75 includes, for example, a CPU (not
shown), the AE motor controller 66, the whole optical unit driving
motor controller 60, the rear lens group driving motor controller
61, the object distance measuring apparatus 64, and the
photometering apparatus 65. The control unit 75 is also connected
to, for example, the zoom operating device 62 and the focus
operating device 63.
In order to guide the flexible printed circuit board 6, the
rectilinear guide barrel 17 further includes, on its inner
peripheral face, a flexible printed circuit board lead-in groove
17h (FPC lead-in groove), which runs parallel to the optical axis O
and guides the flexible printed circuit board 6. The FPC lead-in
groove 17h includes a through hole 17i that passes through the
linear guide barrel 17 at the rear of the FPC lead-in groove
17h.
Also, as shown in FIG. 13, the annular part 22a further includes a
guide groove 22i, which allows the passage of, and rectilinearly
guides, the flexible printed circuit board 6. In FIG. 13, the
flexible printed circuit board is shown using phantom lines to show
its position in the guide groove 22i.
The annular part 22a also supports a spring support part 70, which
resiliently supports the flexible printed circuit board 6. The
spring support part 70 includes two guiding protrusions 70c, which
protrude toward the front of the camera, a spring bearing
protrusion 70a, which is positioned between the two guiding
protrusions 70c, and a spring housing groove 70b, which is provided
at the base of the spring bearing protrusion 70a. As shown in FIG.
21, the rear face of the linear guide member 22 includes two
sliding support holes 22h and a spring hole 22g, which are
positioned between the two sliding supporting holes 22h. The two
guiding protrusions 70c are slidably fitted into the two sliding
supporting holes 22h. A compression spring 71 is placed on the
spring bearing protrusion 70a and is supported in the spring
housing groove 70b. The spring bearing protrusion 70a is then
inserted into the spring hole 22g and is compressed inside spring
hole 22g. The spring support part 70 also includes a guide groove
70d that substantially coincides with the guide groove 22i when the
spring bearing protrusion 70a is inserted into the spring hole
22g.
With the above arrangement, the spring support part 70 is
positioned at the rear of the linear guide member 22 (i.e., the
rear of the first movable barrel 20) such that the flexible printed
circuit board 6 is resiliently supported in a direction parallel to
the optical axis O.
The flexible printed circuit board 6 is defined as including a
number of segments, as follows: a first rectilinear segment 6a,
which extends from the AF/AE shutter unit 21 to the rear of the
linear guide member 22; a first U-shaped segment 6b, which is
formed by bending the flexible printed circuit board 6 forward over
the spring support part 70 and inserting the flexible printed
circuit board 6 into the guide groove 22i (see, for example, FIG.
13) at the rear of the rectilinear guide member 22; a second
rectilinear segment 6c, which extends frontwardly along the FPC
lead-in groove 17h; a second U-shaped segment 6d, which is formed
by bending the flexible printed circuit board 6 toward the rear
around the front end of the FPC lead-in groove 17h; a third
rectilinear segment 6e, which extends rearward along an outer face
17j of the FPC lead-in groove 17h (inside the inner face of the
third movable barrel 16) and, near the rear end of the rectilinear
guide barrel 17, is lead to the inner face of the rectilinear guide
barrel 17 via the through hole 17i; a third U-shaped segment 6f,
which is formed to pass the flexible printed circuit board 6
through the FPC relief hole 12k of the fixed lens barrel block 12;
a fourth rectilinear segment 6g, which extends from the third
U-shaped segment 6f; and a fixed end segment 6h, which is fixed to
the fixed part 12m at the outer side of the fixed lens barrel block
12 (see, in particular FIGS. 15-18).
Further, the flexible printed circuit board 6 is fixed with respect
to the linear guide barrel 17 by securing the third rectilinear
segment 6e to the outer face 17j of the linear guide barrel 17 by,
for example, double-sided tape 73 (FIG. 12).
In other words, the flexible printed circuit board 6 is lead
rearward from the AF/AE shutter unit 21 on the inner side of the
second movable barrel 19, bent forward once at the rear end of the
second movable barrel 19, lead forward inside the FPC lead-in
groove 17h of the linear guide barrel 17, bent along the outer face
17j of the linear guide barrel 17 from the front end of the FPC
lead-in guide groove 17h, adhered to the outer face 17j with the
double-sided tape 73, guided again to the inner face of the
rectilinear guide barrel 17 via the through hole 17i, and then bent
out through the FPC relief hole 12k and attached to the fixing part
12m of the fixed lens barrel block 12.
The fixed end segment 6h of the flexible printed circuit board 6 is
connected to the control unit 75 via a second flexible printed
circuit board (not shown) to make the connection to the control
unit 75 shown by a dotted line in FIG. 8.
As described above, the flexible printed circuit board 6 is bent at
the front end of the FPC lead-in groove 17h and then lead along the
outer face 17j of the rectilinear guide barrel 17 until lead into
the inner face of the rectilinear guide barrel 17 via the through
hole 17i. Since the flexible printed circuit board 6 is held in
place and guided by the FPC lead-in groove 17h on the inner side of
the linear guide barrel 17 and is prevented from moving radially on
the outer face 17j of the linear guide barrel 17 because it is lead
through the through hole 17i, the flexible printed circuit board 6
will not interfere with the follower pin 18, which moves in and is
guided by the lead groove 17b or interfere with the movement of the
second movable barrel 19 or the third movable barrel 16.
In the present embodiment, the relative amount and speed of
movement of the first movable barrel 20 with respect to the second
movable barrel 19 in the optical axis direction during zooming
(advancing/retracting movement along the optical axis O) is set
substantially equal to the relative amount and speed of movement of
the second movable barrel 19 with respect to the third movable
barrel 16. The substantial equality is achieved by setting the
engaging relationship between the third movable barrel 16 and the
fixed lens barrel block 12, the inclination (lead angle) of the
lead groove 17b on the rectilinear guide barrel 17, and the
inclination (lead angle) of the lead groove 19c on the second
movable barrel 19. Note that, the third movable barrel 16 of this
embodiment could also be a stationary portion, such as a housing
for guiding the second movable barrel 19.
In particular, as a non-limiting exemplary arrangement of a
preferred embodiment, the amount of lead of the lead groove 19c
(i.e., the amount by which the first movable barrel 20 moves) is
set to 124 mm and the amount of lead of the lead groove 17b (i.e.,
the amount by which the second movable barrel 19 moves) is set to
122.5 mm. As shown in FIGS. 22-25, the lead grooves 19c and 17b
include linear portions with a fixed lead angle and slip groove
parts 19c' and 17b' that are orthogonal to the optical axis O and
that correspond to the lens accommodation position.
With the above arrangement, the respective amounts of extension of
the first movable barrel 20 and the second movable barrel 19 are
proportional to the amount of rotation of the third movable barrel
16 (and the speed of movement is proportional to the rotation speed
of the whole optical unit driving motor 25). In both the linear
guide barrel 17 and the second movable barrel 19, the lead starting
points for extending the first movable barrel 20 and the second
movable barrel 19 are hypothetical points at a position 3.degree.
from the lens-housed position when the follower protrusion 19a and
the follower pin 24 are respectively positioned at the slip groove
parts 17b' and 19c'.
The rectilinear guide barrel 17 does not rotate, but because the
third movable barrel 16 does rotate, the relative rotation of the
rectilinear guide barrel 17 with respect to third movable barrel
16, due to the action of the rectilinear guide groove 16c, shall be
considered here.
In particular, the third movable barrel 16 is set to rotate by
approximately 70.degree. (i.e., 73.degree. from the lens-housed
position) in order to move the follower protrusion 19a and the
follower pin 24 from the hypothetical starting points to the
positions corresponding to the position at which the zoom lens is
extended the most (tele end). Thus, the extension amount difference
in the relative amounts of extension of the first movable barrel 20
and the second movable barrel 19, in the exemplary arrangement
above, is:
The extension amount difference is compensated for by the spring
support part 70. In particular, since the first U-shaped segment 6b
at the rear end of the second movable barrel 19 (and the linear
guide member 22) is wound around the spring support part 70, the
amount of compensating movement required by the spring support part
70 in the optical axis direction is half of the actual extension
amount difference, that is, for the exemplary arrangement, 0.15 mm.
Thus, when the first rectilinear segment 6a of the flexible printed
circuit board 6 is pulled in the optical axis direction by the
first movable barrel 20 by the above extension amount difference of
0.3 mm, the spring support part 70 is moved in the optical axis
direction by 0.15 mm. That is, the spring support part 70, which is
supported and urged rearward by the compression spring 71, is
adjusted to allow movement by 0.15 mm forward in the optical axis
direction. Over this distance, the percentage change in the urging
force of the compression spring 71 is set to approximately 10%.
FIG. 26 is a graph showing the relationship between the amount of
rotation of the third movable barrel 16 and the relative amount of
advance/retract (amount of extension) of the first movable barrel
20 with respect to the second movable barrel 19 and the relative
amount of advance/retract (amount of extension) of the second
movable barrel 19 with respect to the third movable barrel 16 for
the exemplary arrangement. As can be seen in this graph, the
respective advancing/retracting motions, along the optical axis O,
of the first movable barrel 20 and the second movable barrel 19
vary linearly. In other words, other than in the range of
0.degree.-3.degree., the respective amounts of movement of the
first movable barrel 20 and the second movable barrel 19 are
proportional to the amount of rotation of the third movable barrel
16. The range from 0.degree.-3.degree. corresponds to the movement
from the lens-housed position to the lead starting points
(discussed above, and shown in FIGS. 23 and 25, that is, the curved
parts 19c3 and 17b3, which connect the respective horizontal parts
19c1 and 17b1 and the lead parts 19c2 and 17b2 of the lead grooves
19c and 17b). The point of transition from the curved part to the
lead part corresponds to a rotation angle of 4.367.degree. for the
lead groove 19c and to a rotation angle of 4.848.degree. for the
lead groove 17b in the above example.
Since the first movable barrel 20 and the second movable barrel 19
are substantially equal with regard to the amount of extension for
the same amount of rotation of the third movable barrel 16 (in
other words, for the same time) and their respective
advancing/retracting motions vary linearly, it can be understood
that, during advance or retract (during zooming), the relative
amount and speed of advance/retract along the optical axis O of the
first movable barrel 20 with respect to the second movable barrel
19 is substantially equal to the relative amount and speed of
advance/retract along the optical axis O of the second movable
barrel 19 with respect to the third movable barrel 16. In the
above, the term "substantially equal" means that the error between
the relative amount and speed of the advance/retreat along the
optical axis O of the first movable barrel 20 with respect to the
second movable barrel 19, and the relative amount and speed of
advance/retract along the optical axis O of the second movable
barrel 19 with respect to the third movable barrel 16 is
approximately .+-.0.3%.
As explained above, when the zoom lens barrel 10 is advanced or
retracted, the relative movements of the first movable barrel 20
and of the second movable barrel movable barrel 19 prevent the
slacking of the flexible printed circuit board 6. In particular, as
shown in FIG. 9, initially, the first linear segment 6a is short,
while the second linear segment 6c is long. During advance, the
lengths of the first linear segment 6a and the second linear
segment 6c vary proportionally, such that, at full extension, as
shown in FIG. 8, the first linear segment 6a is long, while the
second linear segment 6c is short. During this advance, the first
U-shaped segment 6b remains in contact with the spring support part
70, and, as explained above, the spring support part 70 is
resiliently mounted to compensate for any slacking of the flexible
printed circuit board 6 that is not controlled by the relationship
of the movements of the first movable barrel 20 and the second
movable barrel 19. The process is reversed during retracting.
Thus, in the present embodiment of the zoom compact camera the
slacking of the flexible printed circuit board 6 is prevented and a
receiving part for receiving any slack is not needed allowing a
more compact camera. Further, by the combination of the FPC lead-in
groove 17h and the through hole 17i, the flexible printed circuit
board 6 is held in position such that the flexible printed circuit
board 6 does not affect the movement of the components of the
camera.
Another preferred embodiment of the zoom compact camera shall now
be described with reference to FIGS. 27 and 28. In this embodiment,
the flexible printed circuit board 6 can be described as including
a number of segments including a first rectilinear segment 6a,
which extends along the inner face of the second movable barrel 19
from the AF/AE shutter unit 21 mounted on the first movable barrel
20 to the rear of the linear guide member 22; a first U-shaped
segment 6b, which is formed by bending the flexible printed circuit
board 6 forward over the spring support part 70 and inserting the
flexible printed circuit board 6 into the guide groove 22g at the
rear of the rectilinear guide member 22 and the second movable
barrel 19; a second rectilinear segment 6c, which extends
frontwardly toward the inner face of the front end of the third
movable barrel 16; a second U-shaped segment 6d, which is formed by
bending the flexible printed circuit board 6 toward the rear around
the front end of the FPC lead-in groove 17h on the linear guide
barrel 17; a third rectilinear segment 6e, which extends rearward
along the outer face 17j of the FPC lead-in groove 17h (the inner
face of the third movable barrel 16) toward the camera body, and is
lead to the inner face of the rectilinear guide barrel 17 via the
through hole 17i; a pair of annular segments 6f1 and 6f2 described
in detail below; a fourth rectilinear segment 6g, which extends
from the annular segment 6f2 along the exterior of the fixed lens
barrel block 12; and a fixed end segment 6h, which is fixed to the
fixed part 12m at the outer side of the fixed lens barrel block
12.
As in the previous embodiment, the flexible printed circuit board 6
is fixed to the outer face 17j of the linear guide barrel 17 by the
double-coated tape 73. Also, the fixed end segment 6h of the
flexible printed circuit board 6 is connected to the control unit
75 via a second flexible printed circuit board (not shown).
In particular, the annular segments 6f1 and 6f2 define holes h1 and
h2 which allow the passage of the photographing light (the light of
the photographing optical system). As shown in FIGS. 29 and 30, the
annular segments 6f1 and 6f2 form a "spectacle-like" form in the
unfolded condition and are foldable at the middle at a joining
segment 6i. The annular segment 6f1 is attached to the third
rectilinear segment 6e and the annular segment 6f2 is attached to
the fourth rectilinear segment 6g. In particular, the annular
segment 6f2 attaches to the fourth rectilinear segment 6g through a
gap between the rear end of the fixed lens barrel block 12 and the
aperture plate 14, such that the through hole 12k described for the
first embodiment is not required.
If, for example, the flexible printed circuit board 6 is further
provided with circuit patterns P1 and P2 (shown in FIG. 29), which
continue over the whole length of the flexible printed circuit
board 6 (not shown), the patterns P1 and P2 can be split to the
left and right sides of the annular segments 6f1 and 6f2 as shown
in FIG. 29. The arrangement of the annular segments 6f1 and 6f2 in
this manner provides a structure which expands and retracts between
a closed position as shown in FIG. 28 and an opened position as
shown in FIG. 27. That is, the annular segments 6f1 and 6f2 extend
and retract in a bellows-like manner (when viewed from the side of
the zoom lens barrel 10) as the first movable barrel 20 advances
and retracts along the optical axis O. In particular, the use of a
combination of circuit patterns P1 and P2 allows the widths (i.e.,
difference between outer diameters and inner diameters) of the
annular segments 6f1 and 6f2 to be smaller than the width of the
other segments of the flexible printed circuit board 6, and, in
particular, smaller than the width of a single flexible printed
circuit board arranged in a spiral manner, thus, taking less space
within the camera. Furthermore, since the photographing light
passes through the holes h1 and h2 of the annular parts 6f1 and
6f2, both adverse light rays at the edges of the photographing
light beam and internal reflection will be reduced.
Although the structure and operation of a zoom compact camera is
described herein with respect to the preferred embodiments and
exemplary structures, many modifications and changes can be made
without departing from the spirit and scope of the invention.
The present disclosure relates to subject matter contained in
Japanese Patent Application Nos. HEI 08-012317, filed on Jan. 26,
1997, HEI 08-027132, filed on Feb. 14, 1996, HEI 08-027133, filed
on Feb. 14, 1996, and HEI 08-057878, filed on Mar. 14, 1996, which
are expressly incorporated herein by reference in their
entirety.
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